A continuing study of relationships between brain and behavior using experimental psychologic and neurologic methods in the analysis of behavioral change in several groups: (a) In adults with focal brain injuries sustained at maturity; (b) adults who have undergone various neurosurgical procedures or are suffering from vascular or neoplastic disease involving the brain; (c) children or young adults who have suffered brain damage early in life. These investigations are supplemented by animal experiments involving cerebral ablations, stimulation, and recording. Special emphasis is placed on perceptual changes, on alteration in motor performance and sensorimotor coordination, and on disturbances of higher processes including language and memory.